Re: Networking proves elusive with Qemu

[Andreas Gustafsson <gson%gson.org@localhost>]

Bob Bernstein wrote:
> Prior to turning to virtualbox I had partial success with Qemu. 
> With Qemu, my *bsd guests' VM's would complete successful boots 
> on this Debian stable host, but the networking never worked.
> 
> There seemed to be a problem with routing, as the nic got its IP 
> address and netmask and broadcast numbers. Pings seemed to send 
> packets to remote hosts but never got any back. Pinging 
> localhost worked ok.
> 
> Then I came across this statement in the Debian Qemu wiki:
> 
> "By default, QEMU invokes the -nic and -user options to add a 
> single network adapter to the guest and provide NATed external 
> Internet access."
> 
> My experience is that this does *not* happen here. I never get 
> the NAT. So, for example, this command-line produces a quite 
> workable NetBSD VM, but once it boots it has no network access:
> 
> # qemu-system-x86_64 -net nic -net user m=256 -cdrom 
> boot-NetBSD-amd-7.0_RC3.iso nbsd.img
> 
> Anybody know what's lacking there?

Qemu's default NATed external Internet access uses a SLIRP-based
user-mode networking stack that doesn't support ICMP, so ping is not
expected to work. Try connecting to a TCP based service like http or
ssh.
-- 
Andreas Gustafsson, gson%gson.org@localhost